Formal Kinetics of Multiple Homogenous Reactions

As it has already been mentioned, often more than one chemical equation is necessary to present all observed components and their transformations. In this case one talks about complex or multiple reactions. One of the simple examples of multiple reactions is a reversible reaction occurring in the reactor, which can be presented in the following way  

The reaction rates depend on the concentrations of the reacting species and can be described by a PRL  

If v = 1 and both reactions are of first order for all the reactants A,-, Equation 2.16 can be rewritten  

A chemical reaction proceeds in the direction in which the free Gibbs energy, G, of the reaction mixture diminishes. When equilibrium is reached  

If the thermodynamic activities of the reactants correspond to their concentrations, the equilibrium constant can be estimated from the second law of thermodynamics  

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